Typical commercial processes for the manufacture of polysaccharide ethers, e.g. hydroxyethyl cellulose, require the use of acids and bases. For example, a base such as, e.g., sodium hydroxide, is typically used to promote the swelling of the polysaccharide, which in turn facilitates the subsequent reaction with an alkylene oxide, e.g., ethylene oxide. After the polysaccharide is reacted with the alkylene oxide to form the polysaccharide ether, the reaction mixture is typically neutralized with a mineral acid or an organic acid, e.g., nitric acid or acetic acid. As a result of the neutralization, a salt, e.g., sodium nitrate or sodium acetate, is formed. Typically, the salt is comprised in an aqueous waste stream which also contains organic solvents used in the process and residues of the polysaccharide.
Often, the salts are recovered from the waste stream and disposed of However, the disposal of such salts may not be environmentally desirable or feasible. Therefore, improved processes for the production of polysaccharide ethers are desired which can convert the salts formed in the processes to their corresponding acids and bases. Preferably, the acids and bases recovered from the processes can be recycled for use in the production of the polysaccharide ethers.